movement disorders - Research .fr

cortex, thalamus, basal ganglia ... Spasticity. — change in reflexes to muscle stretch with a strong velocity component ... uncontrolled spasms. — increase in ...
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MOVEMENT DISORDERS Emmanuel Guigon Institut des Systèmes Intelligents et de Robotique Université Pierre et Marie Curie CNRS / UMR 7222 Paris, France

[email protected] e.guigon.free.fr/teaching.html

3

3. Stroke and rehabilitation BCI/BMI

DEFINITION — EPIDEMIOLOGY • Acute focal injuries to the brain — in ~85% of the cases, interruption to the blood supply (ischemic): neuronal degeneration (infarct) — bleeding (hemorhagic): no tissue destruction, possible restitution

• Prevalence — ~700 000/year in the United States — 3rd leading cause of death — leading cause of disability — 90% of stroke survivors have a deficit — 2/3 in people older than 65

“MOTOR” STROKES Territory of the middle cerebral artery — blood supply to sensory and motor systems, temporal and parietal cortex, thalamus, basal ganglia

MOTOR SYMPTOMS • Paresis/hemiparesis — loss of power of any muscle group — abnormally slow and clumsy movements — complete loss: plegia or paralysis

• Spasticity — change in reflexes to muscle stretch with a strong velocity component — emergence of pathological reflexes and uncontrolled spasms — increase in muscle tone — impairment of voluntary motor function

SYMPTOMS stroke

PwPD

cbm

SYMPTOMS

DEFINITION

akinesia

paucity of movements, delayed movement initiation

apraxia

difficulties in movement planning

ataxia

lack of coordination in absence of muscular weakness

bradykinesia

slowness and reduced amplitude of movements

dysdiadochokinesia

impaired repetitive alternating movements

X

dysmetria

irregularity of movements with undershoots/overshoots

X

hypotonia

low muscle tone

X

hyperreflexia

reduced sensory threshold and larger reflex amplitudes

X

paresis

weakness of voluntary movements

X

postural instability

wide base stance and gait, inability to stand without support

rigidity

steady increase in resistance to passive stretch

spasticity

hypertonia, increased resistance to passive stretch

tremor

intention (during movement) or resting

(1) rest tremor (2) intention tremor: absent during rest, provoked by voluntary movements

X X X

X X X X1

X2

MOTOR DEFICITS End-point trajectory

Coordination arm movements in 2D space

Interjoint coordination

healthy control non-affected arm

affected arm

ELBOW

SHOULDER

Velocity

— Levin, 1996, Brain 119:281

MOTOR DEFICITS Segmentation arm movements in 2D/3D space

— Trombly, 1993, J Neurol Neurosurg Psychiatr 56:40

— Krebs et al., 1999, Proc Natl Acad USA 96:4645

— DeJong et al., 2012, Neurorehabil Neural Repair 26:362

STROKE RECOVERY • Definition improvements in abilities over time, at any of the ICF levels (World Health Organization’s International Classification of Functioning, Disability, and Health), regardless of how these improvements occurred

• Restitution/substitution (true recovery) undamaged brain regions are recruited, which generate commands to the same muscles as were used before the injury e.g. unmasking, through training, of pre-existing corticocortical connections (redundant pathways)

• Compensation use of structures and/or functions different from those used before the injury to achieve a movement goal e.g. using the less-affected arm

STROKE RECOVERY • Spontaneous recovery (——)

learned nonuse • concurrent decrease of spontaneous used of the impaired side • preference for the less affected side learned as a result of unsuccessful repeated attempts in using the affected side

plasticity, brain reorganization (e.g. activation of undamaged regions in the opposite hemisphere)

• Training-dependent recovery (——) task-specific targeted training GLOBAL

100 • amount and type of injury • initial level of recovery

• compensatory use of the lessaffected limb (learned nonuse) • unilateral impairements • ~50% of patients stop here • reduced QoL

TASK-SPECIFIC targeted training physical therapy

long-term functional limitations

irrespective of the kind of intervention

0 early acute

injury-induced changes in the potential for plasticity

prolonged critical period of plasticity

late chronic

PLASTICITY Localized lesion in primary motor cortex behavioral retraining: retrieve food pellets from small wells

no rehabilitation

territory loss — Nudo et al., 1996, Science 272:1791

rehabilitation

territory gain microstimulation maps

STROKE RECOVERY ASSESSMENT Scores — Fugl-Meyer Assessment to quantify the sensorimotor impairment (motor function, sensory function, balance, range of motion of joints, joint pain) on an ordinal scale (0=no; 1=partial; 2=full) — Barthel ADL index: 10 variables describing activities of daily living (ADL) and mobility

— Duncan et al., 1992, Stroke 23:1084

STROKE RECOVERY ASSESSMENT

upper limb

lower limb

Time-dependent recovery

FM = Fugl-Meyer (balance: sitting, standing)

FAC = Functional Ambulation Capacities (walking)

MI = Motricity Index (measure of strength)

ARAT = Action Research Arm Test (recovery of dexterity)

BI = Barthel Index (ADL)

LCT = Letter Cancellation Task (presence of neglect)

— Kwakkel et al., 2006, Stroke 37:2348

STROKE RECOVERY ASSESSMENT Individual variability in arm use after motor training normalized use in immediate group of EXCITE data Normalized MAL AOU (Motor Activity Log Amount of Use) increasing

decreasing

— Hidaka et al., 2012, PLoS Comput Biol 8:e1002343

no change

STROKE RECOVERY • Smoothness robot therapy — 5 h/week for 4 weeks (acute), 3 h/week for 6 weeks (chronic)

— Rohrer et al., 2002, J Neurosci 22:8297

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+

+

+ smooth mean speed peak speed mean arrest period ratio proprotion of time above a threshold velocity

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+ negative of the number of velocity peaks

t2[td;tv] 1 ⇢ 2⌘nmaJ = dv d v (t2 t1)vpeak t dt2 dt where {vmaximametrics } = v(t) : = 0 and 2 < 0 ⇢ ⌘pm =dv# {vmaxima}d2 v Smoothness dt where {vdt vpeak = max v(t)= 0 and v(t)